April 27, 2005
Dolores Beasley/Erica Hupp
Headquarters, Washington
(Phone: 202/358-1753/1237)
D.C. Agle
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/ 393-9011)
RELEASE: 05-108
NASA'S DEEP IMPACT SPACECRAFT SPOTS ITS QUARRY, STALKING BEGINS
Sixty-nine days before it gets up-close-and-personal with a comet,
NASA's Deep Impact spacecraft successfully photographed its quarry,
comet Tempel 1, at a distance of 39.7 million miles.
The image, the first of many comet portraits it will take over the
next 10 weeks, will aid Deep Impact's navigators, engineers and
scientists as they plot their final trajectory toward an Independence
Day encounter.
"It is great to get a first glimpse at the comet from our spacecraft,"
said Deep Impact principal investigator, Dr. Michael A'Hearn of the
University of Maryland, College Park, Md. "With daily observations
beginning in May, Tempel 1 will become noticeably more impressive as
we continue to close the gap between spacecraft and comet. What is
now little more than a few pixels across will evolve by July 4 into
the best, most detailed images of a comet ever taken," he added.
The ball of dirty ice and rock was detected on April 25 by Deep
Impact's Medium Resolution Instrument on the very first attempt.
While making the detection, the spacecraft's camera saw stars as dim
as 11th visual magnitude, more than 100 times dimmer than a human can
see on a clear night.
"This is the first of literally thousands of images we will take of
Tempel 1 for both science and navigational purposes," said deputy
program manager Keyur Patel at NASA's Jet Propulsion Laboratory,
Pasadena, Calif. "Our goal is to impact a 39 inch long spacecraft
into about a 4 mile wide comet that is bearing down on it at 6.3
miles per second, while both are 83 million miles away from Earth. By
finding the comet as early and as far away as we did is a definite
aid to our navigation."
Deep Impact is comprised of two parts, a "flyby" spacecraft and a
smaller "impactor." The impactor will be released into the comet's
path for a planned high-speed collision on July 4. The crater
produced by the impact could range in size from the width of a large
house up to the size of a football stadium and from 2 to 14 stories
deep. Ice and dust debris will be ejected from the crater, revealing
the material beneath.
The Deep Impact spacecraft has four data collectors to observe the
effects of the collision – a camera and infrared spectrometer
comprise the High Resolution Instrument, a Medium Resolution
Instrument, and a duplicate of that camera on the impactor (called
the Impactor Targeting Sensor-ITS) that will record the vehicle's
final moments before it is run over by comet Tempel 1 at a speed of
about 23,000 miles per hour.
The overall Deep Impact mission management for this Discovery class
program is conducted by the University of Maryland. Deep Impact
project management is handled by the Jet Propulsion Laboratory. The
spacecraft was built for NASA by Ball Aerospace & Technologies
Corporation, Boulder, Colo.
To view the image on the Internet, visit:
http://www.nasa.gov/deepimpact
For more information about Deep Impact on the Internet, visit:
http://www.nasa.gov/deepimpact
For more information about NASA on the Internet, visit:
http://www.nasa.gov
-end-